Indices
- Column indices
- Unique indices
- Indices with multiple columns
- Spatial Indices
- Disabling synchronization
Column indices
You can create a database index for a specific column by using @Index
on a column you want to make an index.
You can create indices for any columns of your entity.
Example:
import {Entity, PrimaryGeneratedColumn, Column, Index} from "typeorm";
@Entity()
export class User {
@PrimaryGeneratedColumn()
id: number;
@Index()
@Column()
firstName: string;
@Column()
@Index()
lastName: string;
}
You can also specify an index name:
import {Entity, PrimaryGeneratedColumn, Column, Index} from "typeorm";
@Entity()
export class User {
@PrimaryGeneratedColumn()
id: number;
@Index("name1-idx")
@Column()
firstName: string;
@Column()
@Index("name2-idx")
lastName: string;
}
Unique indices
To create an unique index you need to specify { unique: true }
in the index options:
Note: CockroachDB stores unique indices as
UNIQUE
constraints
import {Entity, PrimaryGeneratedColumn, Column, Index} from "typeorm";
@Entity()
export class User {
@PrimaryGeneratedColumn()
id: number;
@Index({ unique: true })
@Column()
firstName: string;
@Column()
@Index({ unique: true })
lastName: string;
}
Indices with multiple columns
To create an index with multiple columns you need to put @Index
on the entity itself
and specify all column property names which should be included in the index.
Example:
import {Entity, PrimaryGeneratedColumn, Column, Index} from "typeorm";
@Entity()
@Index(["firstName", "lastName"])
@Index(["firstName", "middleName", "lastName"], { unique: true })
export class User {
@PrimaryGeneratedColumn()
id: number;
@Column()
firstName: string;
@Column()
middleName: string;
@Column()
lastName: string;
}
Spatial Indices
MySQL and PostgreSQL (when PostGIS is available) both support spatial indices.
To create a spatial index on a column in MySQL, add an Index
with spatial:
true
on a column that uses a spatial type (geometry
, point
, linestring
,
polygon
, multipoint
, multilinestring
, multipolygon
,
geometrycollection
):
@Entity()
export class Thing {
@Column("point")
@Index({ spatial: true })
point: string;
}
To create a spatial index on a column in PostgreSQL, add an Index
with spatial: true
on a column that uses a spatial type (geometry
, geography
):
export interface Geometry {
type: "Point";
coordinates: [Number, Number];
}
@Entity()
export class Thing {
@Column("geometry", {
spatialFeatureType: "Point",
srid: 4326
})
@Index({ spatial: true })
point: Geometry;
}
Disabling synchronization
TypeORM does not support some index options and definitions (e.g. lower
, pg_trgm
) because of lot of different database specifics and multiple
issues with getting information about exist database indices and synchronizing them automatically. In such cases you should create index manually
(for example in the migrations) with any index signature you want. To make TypeORM ignore these indices during synchronization use synchronize: false
option on @Index
decorator.
For example, you create an index with case-insensitive comparison:
CREATE INDEX "POST_NAME_INDEX" ON "post" (lower("name"))
after that, you should disable synchronization for this index to avoid deletion on next schema sync:
@Entity()
@Index("POST_NAME_INDEX", { synchronize: false })
export class Post {
@PrimaryGeneratedColumn()
id: number;
@Column()
name: string;
}